【正文】 lves can operate anywhere between 0% and 100% ? In order to have an equal loopgain over the whole operating range a linear valve is required ? This will allow for the fastest tuning leading to smaller surge margins Stroke speed and characteristic of the antisurge valve 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew ? The speed of approaching surge is high ? The transmitter type and brand should be selected based on two major factors: – Reliability – Speed of response ? Desired rise time for Dp (flow) transmitters is 200 ms or less – Pressure step is 100% – The first order response (63%) is less than 200 ms ? Desired rise time for pressure transmitters is 500 ms or less Response time of the FMD transmitter In only 400 ms, DPO dropped by 14%, with a 2% change in DPc 100% 0 100% 0 100% 0 1 SEC. DPo A C D B Pd A C D B DPc A C D B Time Actual pressure Transmitter output 63% response 1 (1/e) t1 is less than 200 ms 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Process 1A UIC VSDS Section 1 VSDS Section 1 Suction Header A LSIC out RSP Serial work RSP B LSIC 1 MPIC Serial work Serial work Section 2 Section 2 2A UIC 1B UIC 1B UIC Serial work Serial work out Train B Train A ? How to operate equidistant from the Surge Control Line (SCL) when there is more than one section per machine ??? Select per train in the loadsharing controller the section closest to the SCL By selecting the section closest to the SCL it is guaranteed that the other section on the same train is not in recycle Equidistant Loadsharing for multisection pressors Share the load equal DEV’s for both trains on the section closest to SCL169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew ? Machines operate at same Rc since suction and discharge of both machines are tied together PICSP The DEV is a dimensionless number representing the distance between the operating point and the Surge Control Line ? Lines of equal DEV can be plotted on the performance curves as shown DEV = 0 Machines are kept at the same relative distance to the Surge Control Line (SCL) ? This means in practice the same DEV for both machines DEV1 DEV2 Recycle will only start when all machines are on their SCL Since DEV is dimensionless all sorts of machines can be mixed: small, big, axials, centrifugals The DEV will be the same for all machines but they will operate at different speeds and flow rates SCL = Surge Control Line Rc,1 qr,1 2 Rc,2 qr,2 2 Compressor 1 Compressor 2 Dev1 = Dev2 Q1 = Q2 N1 = N2 Notes: ? Maximum turndown (energy savings) without recycle or blowoff ? Minimizes the risk of surge since all machines absorb part of the disturbance ? Automatically adapts to different size machines ? CCC patented algorithm Equidistant Loadsharing Parallel Compressor Control 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Process PIC 1 1 UIC Compressor 1 VSDS Compressor 2 Suction header Notes ? Performance controllers act independent of antisurge control ? Higher capital cost due to extra Flow Measurement Devices (FMD) ? Higher energy costs due to permanent pressure loss across FMD’s 1 FIC 2 FIC 2 UIC out out RSP RSP out RSP Equal Flow Division Loadsharing Flow Diagram for Control Process VSDS 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Rc,1 qr,1 2 Rc,2 qr,2 2 Compressor 1 Compressor 2 ? Machines operate at same Rc since suction and discharge of both machines are tied together PICSP Base load one or more pressors let the other(s) absorb the load swings Swing machine Base machine machine is fully loaded and runs without recycle QC,2= QP,2 Swing machine can be running with recycleQC,1 QP,1 where: QP = Flow to process QC= Total pressor flow QC QP = Recycle flow Load could be redivided to eliminate recycle QP,1 QP,1 + QP,2 = QP,1 + QP,2 注： ? 基本負(fù)荷法效率較低。 – 最低的能耗 – 在啟動(dòng)或停開(kāi)單一機(jī)組時(shí)將所帶來(lái)的工藝擾動(dòng)降到最低。 2022 Compressor Controls Corporation Menu Fwd Prev Rew ? 在壓縮機(jī)網(wǎng)絡(luò)中，壓縮機(jī)通常并聯(lián)運(yùn)行，有時(shí)也有串聯(lián)運(yùn)行 ? 形成網(wǎng)絡(luò)運(yùn)行的目的包括： – 備份 – 靈活操作 – 增加額外的能力 ? 通常注重單元機(jī)組的運(yùn)行而忽略網(wǎng)絡(luò)的優(yōu)化控制 ? 壓縮機(jī)制造商通常集中于單元機(jī)組的控制。 2022 Compressor Controls Corporation Menu Fwd Prev Rew 負(fù)荷分配控制 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew 并聯(lián)機(jī)組控制系統(tǒng)的目標(biāo)是： ? 保持主性能變量穩(wěn)定（壓力或流量） ? 將負(fù)荷優(yōu)化分配到網(wǎng)絡(luò)中的各臺(tái)機(jī)組上，同時(shí)： – 發(fā)生喘振的機(jī)率最低。 基本負(fù)荷法 169。 ? 基本負(fù)荷法并不是推薦的方式 基本負(fù)荷法控制 QP,2 169。 2022 Compressor Controls Corporation Menu Fwd Prev Rew Notes ? All controllers are coordinating control responses via a serial work ? Minimizes recycle under all operating conditions Process 1 UIC VSDS Compressor 1 VSDS